If you are looking for a complete, free and powerful server for your network, Univention Corporate Server (UCS) is for you. The new version of UCS 4.1.1 has been released which comes with many improvements, and bug fixes.

Univention Corporate Server is a Debian based Linux that is stable, rich features, and its free. If you need a professional supports and more features for your company, its also available in paid version. Univention Corporate Server is a good Windows Server replacement. The Samba Domain Controller is now improved with the latest Samba 4.3.3. You can easily build or migrate your Active Directory using UCS.